// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Hardware monitoring driver for Texas Instruments TPS53679
 *
 * Copyright (c) 2017 Mellanox Technologies. All rights reserved.
 * Copyright (c) 2017 Vadim Pasternak <vadimp@mellanox.com>
 */

#include <linux/bits.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include "wb_pmbus.h"

enum chips {
    tps53647, tps53667, tps53679, tps53681, tps53688, tps53622
};

#define TPS53647_PAGE_NUM             1

#define TPS53679_PROT_VR12_5MV        0x01 /* VR12.0 mode, 5-mV DAC */
#define TPS53679_PROT_VR12_5_10MV     0x02 /* VR12.5 mode, 10-mV DAC */
#define TPS53679_PROT_VR13_10MV       0x04 /* VR13.0 mode, 10-mV DAC */
#define TPS53679_PROT_IMVP8_5MV       0x05 /* IMVP8 mode, 5-mV DAC */
#define TPS53679_PROT_VR13_5MV        0x07 /* VR13.0 mode, 5-mV DAC */
#define TPS53679_PAGE_NUM             2

#define TPS53681_DEVICE_ID            0x81

#define TPS53681_PMBUS_REVISION       0x33

#define TPS53681_MFR_SPECIFIC_20      0xe4    /* Number of phases, per page */

static const struct i2c_device_id tps53679_id[];

static int tps53679_identify_mode(struct i2c_client *client,
                  struct pmbus_driver_info *info)
{
    u8 vout_params;
    int i, ret;

    for (i = 0; i < info->pages; i++) {
        /* Read the register with VOUT scaling value.*/
        ret = wb_pmbus_read_byte_data(client, i, PMBUS_VOUT_MODE);
        if (ret < 0)
            return ret;

        vout_params = ret & GENMASK(4, 0);

        switch (vout_params) {
        case TPS53679_PROT_VR13_10MV:
        case TPS53679_PROT_VR12_5_10MV:
            info->vrm_version[i] = vr13;
            break;
        case TPS53679_PROT_VR13_5MV:
        case TPS53679_PROT_VR12_5MV:
        case TPS53679_PROT_IMVP8_5MV:
            info->vrm_version[i] = vr12;
            break;
        default:
            return -EINVAL;
        }
    }

    return 0;
}

static int tps53679_identify_phases(struct i2c_client *client,
                    struct pmbus_driver_info *info)
{
    int ret;

    /* On TPS53681, only channel A provides per-phase output current */
    ret = wb_pmbus_read_byte_data(client, 0, TPS53681_MFR_SPECIFIC_20);
    if (ret < 0)
        return ret;
    info->phases[0] = (ret & 0x07) + 1;

    return 0;
}

static int tps53679_identify_chip(struct i2c_client *client,
                  u8 revision, u16 id)
{
    u8 buf[I2C_SMBUS_BLOCK_MAX];
    int ret;

    ret = wb_pmbus_read_byte_data(client, 0, PMBUS_REVISION);
    if (ret < 0)
        return ret;
    if (ret != revision) {
        dev_err(&client->dev, "Unexpected PMBus revision 0x%x\n", ret);
        return -ENODEV;
    }

    ret = i2c_smbus_read_block_data(client, PMBUS_IC_DEVICE_ID, buf);
    if (ret < 0)
        return ret;
    if (ret != 1 || buf[0] != id) {
        dev_err(&client->dev, "Unexpected device ID 0x%x\n", buf[0]);
        return -ENODEV;
    }
    return 0;
}

/*
 * Common identification function for chips with multi-phase support.
 * Since those chips have special configuration registers, we want to have
 * some level of reassurance that we are really talking with the chip
 * being probed. Check PMBus revision and chip ID.
 */
static int tps53679_identify_multiphase(struct i2c_client *client,
                    struct pmbus_driver_info *info,
                    int pmbus_rev, int device_id)
{
    int ret;

    ret = tps53679_identify_chip(client, pmbus_rev, device_id);
    if (ret < 0)
        return ret;

    ret = tps53679_identify_mode(client, info);
    if (ret < 0)
        return ret;

    return tps53679_identify_phases(client, info);
}

static int tps53679_identify(struct i2c_client *client,
                 struct pmbus_driver_info *info)
{
    return tps53679_identify_mode(client, info);
}

static int tps53681_identify(struct i2c_client *client,
                 struct pmbus_driver_info *info)
{
    return tps53679_identify_multiphase(client, info,
                        TPS53681_PMBUS_REVISION,
                        TPS53681_DEVICE_ID);
}

static int tps53681_read_word_data(struct i2c_client *client, int page,
                   int phase, int reg)
{
    /*
     * For reading the total output current (READ_IOUT) for all phases,
     * the chip datasheet is a bit vague. It says "PHASE must be set to
     * FFh to access all phases simultaneously. PHASE may also be set to
     * 80h readack (!) the total phase current".
     * Experiments show that the command does _not_ report the total
     * current for all phases if the phase is set to 0xff. Instead, it
     * appears to report the current of one of the phases. Override phase
     * parameter with 0x80 when reading the total output current on page 0.
     */
    if (reg == PMBUS_READ_IOUT && page == 0 && phase == 0xff)
        return wb_pmbus_read_word_data(client, page, 0x80, reg);
    return -ENODATA;
}

static struct pmbus_driver_info tps53679_info = {
    .format[PSC_VOLTAGE_IN] = linear,
    .format[PSC_VOLTAGE_OUT] = vid,
    .format[PSC_TEMPERATURE] = linear,
    .format[PSC_CURRENT_OUT] = linear,
    .format[PSC_POWER] = linear,
    .func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_IIN | PMBUS_HAVE_PIN |
        PMBUS_HAVE_STATUS_INPUT |
        PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |
        PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT |
        PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP |
        PMBUS_HAVE_POUT,
    .func[1] = PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |
        PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT |
        PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP |
        PMBUS_HAVE_POUT,
    .pfunc[0] = PMBUS_HAVE_IOUT,
    .pfunc[1] = PMBUS_HAVE_IOUT,
    .pfunc[2] = PMBUS_HAVE_IOUT,
    .pfunc[3] = PMBUS_HAVE_IOUT,
    .pfunc[4] = PMBUS_HAVE_IOUT,
    .pfunc[5] = PMBUS_HAVE_IOUT,
};

static int tps53679_probe(struct i2c_client *client)
{
    struct device *dev = &client->dev;
    struct pmbus_driver_info *info;
    enum chips chip_id;

    if (dev->of_node)
        chip_id = (enum chips)of_device_get_match_data(dev);
    else
        chip_id = i2c_match_id(tps53679_id, client)->driver_data;

    info = devm_kmemdup(dev, &tps53679_info, sizeof(*info), GFP_KERNEL);
    if (!info)
        return -ENOMEM;

    switch (chip_id) {
    case tps53647:
    case tps53667:
        info->pages = TPS53647_PAGE_NUM;
        info->identify = tps53679_identify;
        break;
    case tps53679:
    case tps53688:
	case tps53622:
        info->pages = TPS53679_PAGE_NUM;
        info->identify = tps53679_identify;
        break;
    case tps53681:
        info->pages = TPS53679_PAGE_NUM;
        info->phases[0] = 6;
        info->identify = tps53681_identify;
        info->read_word_data = tps53681_read_word_data;
        break;
    default:
        return -ENODEV;
    }

    return wb_pmbus_do_probe(client, info);
}

static const struct i2c_device_id tps53679_id[] = {
    {"wb_tps53647", tps53647},
    {"wb_tps53667", tps53667},
    {"wb_tps53679", tps53679},
    {"wb_tps53681", tps53681},
    {"wb_tps53688", tps53688},
    {"wb_tps53622", tps53622},
    {}
};

MODULE_DEVICE_TABLE(i2c, tps53679_id);

static const struct of_device_id __maybe_unused tps53679_of_match[] = {
    {.compatible = "ti,wb_tps53647", .data = (void *)tps53647},
    {.compatible = "ti,wb_tps53667", .data = (void *)tps53667},
    {.compatible = "ti,wb_tps53679", .data = (void *)tps53679},
    {.compatible = "ti,wb_tps53681", .data = (void *)tps53681},
    {.compatible = "ti,wb_tps53688", .data = (void *)tps53688},
    {.compatible = "ti,wb_tps53622", .data = (void *)tps53622},
    {}
};
MODULE_DEVICE_TABLE(of, tps53679_of_match);

static struct i2c_driver tps53679_driver = {
    .driver = {
        .name = "wb_tps53622",
        .of_match_table = of_match_ptr(tps53679_of_match),
    },
    .probe_new = tps53679_probe,
    .remove = wb_pmbus_do_remove,
    .id_table = tps53679_id,
};

module_i2c_driver(tps53679_driver);

MODULE_AUTHOR("support");
MODULE_DESCRIPTION("PMBus driver for Texas Instruments TPS53679");
MODULE_LICENSE("GPL");
